The reverse transcriptase protein is abundant in many malignancies. In almost 25% of patients with fourth-line refractory metastatic colorectal cancer, single-agent lamivudine, a reverse transcriptase inhibitor, prevented disease progression.
These findings support the development of reverse transcriptase inhibitors as a new class of cancer medicines.
The power of lamivudine in disease progression of colorectal cancer
New clinical research demonstrated that lamivudine, a reverse transcriptase inhibitor often used in HIV treatment, prevented disease progression in 25% of patients with metastatic colorectal cancer who were on their fourth line of treatment, as per ScienceDaily.
The trial's findings, which were published in Cancer Discovery, pointed to an unexpectedly promising route in cancer treatment, not only for colorectal cancer.
The study comprised 32 patients with advanced metastatic colorectal cancer that had developed despite four rounds of chemotherapy.
The usual HIV-approved dosage of lamivudine was given to the first nine individuals.
"We noticed signals of disease stability after giving them only this one medicine and nothing else," said co-senior author David T. Ting, MD, of the Mass General Cancer Center.
Another 23 patients were given lamivudine treatment when the dose was adjusted fourfold, and it was well tolerated.
At the end of the experiment, 9 of the 32 patients, or 28%, exhibited illness stability or mixed response, according to the researchers.
According to Ting, this showed that HIV medicine may be repurposed as an anti-cancer treatment in patients with metastatic disease.
Despite the fact that the researchers did not notice rumor reduction, the findings are encouraging.
Over the last 10 years, the first indications to this unusual drug trial have emerged in Ting's lab and those of his partners.
The researchers revealed that up to 50% of a tumor's DNA was made up of "repetitive elements," which have been previously thought to be "junk DNA," and that only cancer cells, not healthy cells, generated these repetitive elements.
Colorectal tumors, as well as malignancies of the esophagus, lung, and other organs, create a lot of repeating features.
These repeating components produce massive amounts of RNA, which multiply in a viral-like life cycle by reverse transcription into the repeatome, as Ting defined it.
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Sensitivity of colorectal cancer cells to lamivudine
Ting discovered that colorectal cancer cells were susceptible to lamivudine in preclinical experiments, limiting their capacity to migrate.
The researchers also observed that the medication caused DNA damage and interferon reactions in tumor cells, indicating that it provoked an inflammatory response.
Ting theorized that combining reverse transcriptase inhibitor medication with immunotherapy would promote immune cells to get engaged in certain malignancies, albeit this has not been verified or analyzed in this experiment.
According to research, the incidence of colon, breast, and prostate cancer was much lower among HIV patients undergoing lifelong three-drug antiretroviral treatment in the United States than in the general population.
This type of therapy, according to Ting, might prevent cancer or recurrence, or change a crippling metastatic disease into a chronic condition similar to HIV.
They conducted the research to see whether they might discover something useful about cancer cell biology, and in the process, they discovered this unexpected, extremely hopeful finding, according to Ting.
The scientist is aiming to start a bigger research involving a three-drug reverse transcriptase inhibitor combination as part of the Phase III since disease stability in a cancer patient group this advanced with only one treatment is exceedingly rare.
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